Combined exposing and developing apparatus for photoprints



Oct. 6, 1959 J. HORN ETAL 2,907,259 COMBINED EXPOSING AND DEVELOPINGAPPARATUS FOR PHOTOPRINTS Filed March 26, 1956 v 2 Sheets-Sheet 1 24 l LI 2 c 5 6 III 9 B l6 K 2 m g k 0 0 0 0 4 o o o o o J 0000 O I 0 O lJNVENTOR. JOSEF HORN KURT JONS J. HORN ETAL Oct. 6, 1959 COMBINEDEXPOSING AND DEVELOPING APPARATUS FOR PHOTOPRINTS 2 Sheets-Sheet 2 FiledMarch 26, 1956 INVENTOR.

JOSEF HORN 35A A KURT JQNS EORNEY COMBINED EXPOSING AND DEVELOPINGAPPARATUS FOR PHOTOPRINTS Josef Horn and Kurt Jiins, Wiesbaden-Biebrich,Germany, assignors, by mesne assignments, to Keutfel & Esser Co.,Hoboken, N.J., a corporation of New Jersey Application March 26, 1956,Serial No. 573,998 Claims priority, application Germany April 2, 1955 1Claim. (Cl. 95--77.5)

The present invention is concerned with a combined exposing anddeveloping apparatus for photoprints in which the light sensitive papersafter exposure are developed with a gaseous developer, preferablygaseous ammonia.

Such combined apparatuses are already known and in use in the art ofmaking photoprints. Originally, exposure and development were performedin two separate apparatuses. However, when designing an apparatus inwhich both, exposure as well as ammonia development, were to beperformed, several problems had to be solved. One of them was totransfer in an advantageous way the exposed material from the exposuresection of the apparatus to the development section; another was todevise a practical method for separating the exposed paper from theoriginal.

- In one of the known combined apparatuses, the light sensitive papertogether with the original are introduced at the front side of theapparatus, and the exposed and developed paper, i.e. the finished copy,as well as the original are issued separately at the front side. In thisknown apparatus, the light sensitive paper together with the originalare conveyed to a rotatable exposing cylinder lying parallel to thefront side of the apparatus by means of a system of endless conveyorbelts, then are carried around part of the cylinder circumference whilelying on the curved surface of the cylinder, and thereafter are carriedaway from the cylinder at a place lying above the feeding place. By asuction device the exposed paper and the original are separated fromeach other, and the original is issued at the front side of theapparatus. By means of an endless conveyer belt the exposed paper isthen pressed against the perforated bottom of a tank containing thegaseous developer from underneath with its sensitized surface turnedupwards and slid along the perforated bottom of the tank. Thus theexposed paper is developed by the developing gases penetrating throughthe holes in the bottom of the tank. The finished copy is finallytransported towards the front side of the apparatus and issued there.

Now it has been found that a combined exposing and developing apparatusis improved if its parts are arranged in a different way from the priorart construction described above. Thus, in the apparatus according tothe present invention, the tank for holding the gaseous developer isarranged behind the exposing cylinder about level with it, and theperforated wall, which is the developing surface of the tank, faces theexposing cylinder. Further the endless conveyer belt, which transportsthe exposed paper to the developing tank and then along its developingsurface, is arranged as to move above the exposing cylinder, then arounda guide roller which deviates theconveyer belt downwards to thedeveloping surface and then along the latter. Further there is arrangedabove the above mentioned conveyer belt another endless band conveyersystem which may be composed of a plurality of endless bands and whichis lying on the first mentioned conveyer belt.

Further it has been found that for accurate guidance of United StatesPatent the photo prints an apparatus according to the present inventionis of special advantage in which a sheet metal guide which is providedwith slot-like recesses confining finger-like pieces of the sheet metalguide passes from above and behind said guide roller through thesecondmentioned conveyer band system whereby the individual bands of thesecond conveyer band system run through one of the slot-like recessesand the finger-like pieces of the sheet metal guide pass through thespaces between the individual bands of the second conveyer band systemand bend around the guide roller in the direction towards the developingsurface, thus guiding the papers deviated around the guide roller intothe space between the perforated developing surface and that part of theconveyer belt which is sliding thereon.

Fig. 1 is a view in cross sectional elevation of a simplified schematicform of the apparatus according to the present invention.

Fig. 2 is a view in plan of the apparatus showing in particular thearrangement of the second mentioned conveyer band system lying above theconveyer belt, and of the sheet metal guide provided with recesses, partof the upper portion of each conveyer band being shown cut away topermit an unobstructed view of the sheet metal guide.

Fig. 3 is a view in enlarged plan of a part of Fig. 2 with parts brokenaway.

The light sensitive paper together with the original lying thereon arefed into the front side of the apparatus as shown at a feed plate A. Theoriginal and exposed sheet after passing around the exposing cylinder 2both leave the apparatus at a point B on the front side of theapparatus. The original, which now lies beneath the exposed lightsensitive paper, falls down onto the feed plate, while the exposed paperis manually re-fed into the apparatus at C with its image side turnedupwards and, after development, leaves the apparatus at D also at thefront side.

The light sensitive paper fed to the apparatus at A is exposed throughthe Original to the light of a tubular light source 1, while rotatingfor a certain distance with the rotating exposing cylinder 2, againstwhich the paper is. pressed by means of the endless conveyer belt 4. Areflector 3 is provided to make certain that exposure of the paper isperformed only during that portion of its travel where it is firmlypressed against cylinder 2 by means of conveyer belt 4. Conveyer belt 4is led by four rolls (rolls 5, 6, 7 and 8) of which roll 5 is driven androll 6 is a tightening roll. At B, after the exposure is complete,original and exposed paper are wiped oil the exposing cylinder by meansof a Wiper 9. The exposure section of the apparatus is screened againstthe other parts of the apparatus by a casing 10, which in particularprevents the access of developing gases escaping from the developingsection.

The tank 11 for holding the ammonia which serves as a developing gas isprovided with a perforated wall 12. The ammonia gas, which is generatedby evaporating ammonia water in the evaporation trough 13 heated bymeans of the heating rod 14, flows through the perforated wall andcontacts exposed papers passing along that wall, whereby the papers aredeveloped. Preferably, the perforated wall 12 of the tank 11 is inclinedas shown in such a way that it approaches closer to the front of theapparatus at the bottom. Advantageously, additional heating rods 15 areprovided by which the gas tank 11 and the perforated wall 12 may beheated to prevent condensation of water at the perforated wall.

The 7-shape conveyer belt 16 transports the exposed paper from theexposing cylinder 2 to a place above the perforated wall 12 and fromthere along the latter. The conveyer belt 16 is led by four rolls (17,18, 19 and 20) of which roll 20 is a tightening roll and at least one ofthe 16 curves around the guide roller 18 and subsequently passes alongthe perforated wall 12. When no paper is being transported along theperforated wall 12, the holes in the latter are tightly sealed by theelastic endless conveyer belt 16.

At the place Where the prints change direction above the perforated wall12, a sheet metal guide 24 provided with recesses is mounted whichassures that the paper is guided into the space between the conveyerbelt 16 and the perforated wall 12. Fingers 25 of the sheet metal guide24 protrude from above into the spaces between the single be'lts 23, andthen at a certain distance bend around roll 18 and finally aim towardsthe space between roll 18 and perforated wall 12. After development thecopies are carried to a chute 26 and from there to the outlet D at thefront side of the apparatus.

Apart from the two conveyer systems, belt 16 and bands 23 of whichpartially are lying on each other, and the conveyer system in theexposure section, the apparatus according to the present invention needsno further devices for the transportation of the papers or originals,such as compressed air jets or suction devices. In spite of this theoperation of the apparatus is very simple. All steps of the process,i.e. feeding the light sensitive paper together with the original intothe apparatus, refeeding the exposed paper from the exposing to thedevelopment section, and taking off the original used and the finishedcopy, are done from the front side of the apparatus, a very importantfeature when the apparatus is to be operated by a sitting person in anoffice. Another advantage in this connection is that the finished copiesissue at a point beneath the feed table and can thus be immediately seenby the operator. A further advantage of the apparatus according to thepresent invention is its low height due to the special arrangement ofthe exposing cylinder and the tank for the developing gas. A furtherfeature of the ap paratus, which is of special advantage for ofiice use,is that the developing surface may be tilted in the approved manner thusadmitting developing gases of a very low degree of humidity to thepaper, so that only very little ammonia adheres to the finished copies.If a suitable developing 4 temperature is maintained, developing time isshort and thus operational efficiency of the apparatus great.

Having thus described the invention, what is claimed is:

A combined exposing and developing apparatus of small outside dimensionscomprising an enclosure having openings on the front side for theinsertion and removal of light sensitive paper and an original to becopied, a light transmitting cylinder rotatably mounted closely adjacentthe front of the enclosure between the top and bottom thereof, a firstconveyer belt extending around more than half of the cylinder formaintaining the original and paper in contact therewith and to providefor insertion of the paper and original at the lower portion thereof andremoval of the paper and original from the upper portion, a source oflight within the cylinder for exposing the paper through the original,,a second conveyer belt arranged in generally 7-shape and extending fromadjacent the top of the cylinder inwardly into the casing anddownwardlyat anincline toward the front of the casing, the entrance andexit of the first conveyer and the entrance of said 7-shape conveyerbeing substantially the same distance from the front side of theenclosure, the parts being so dimensioned and so positioned that asubstantial part of the cylinder lies within the legs of the 7-shapeconveyer, a third conveyer including a plurality of spaced substantiallycoplanar belts arranged to coact with the upper run of the secondconveyer, a plurality of fingers extending from the spaces between thebelts of the third conveyer and guiding around the apex of the 7-shapeconveyer, a perforated wall extending downwardly from said fingers andarranged to confine the paper between itself and the downwardlyextending run of the 7-shape conveyer, a tank extending rearwardly anddownwardly from said perforated wall for confining vapors to contact thepaper fed between said perforated wall and said downwardly extending runof said 7-shape conveyer, and means to receive the paper from the lowerend of said perforated plate and the lower end of said downwardlyextending run of the said 7-shape conveyer.

References Cited in the file of this patent UNITED STATES PATENTS2,317,655 Van Den Broek Apr. 27, 1943 2,457,753 Trump Dec. 28, 19482,559,159 Hruby July 3, 1951 2,574,215 Kunstadter Nov. 6, 1951 2,641,980Brunk June 16, 1953 2,735,346 Frantz Feb. 21, 1956

